This invention relates to bicell batteries.
This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws xe2x80x9cto promote the progress of science and useful artsxe2x80x9d (Article 1, Section 8).
Batteries based on aqueous, non-aqueous and solid electrolytes are manufactured as power sources for microelectronic and portable electronic equipment. Size and weight are typically significant considerations in a design. Some designs include a plurality of thin layers which are laminated together. Some batteries include several electrolytic cells in which the current from each of the cells is accumulated in parallel by respective anode and cathode current collectors. In certain designs, the current collectors are gathered and welded to respective terminal strips. The battery components can be sealed or enveloped in a heat-sealable laminate which serves as the protective housing for the battery, with the welded terminal strips projecting therefrom for electrically engaging the battery.
One type of battery construction is a bicell. An individual bicell has two counter electrodes positioned on either side of an intermediate electrode. Pluralities of bicells can be combined in series or parallel in a single battery. Individual bicells typically include current collectors embedded in the respective electrode active materials. The individual current collectors typically have extensions or projections which extend outwardly from the electrode active material. The counter electrode extensions typically are designed to overlap, and are electrically connected together. The middle or intermediate current collector extension is typically on the same side of the construction as the counter electrode extensions but remotely located therefrom. If the battery comprises multiple bicells connected in parallel, for example, the respective positive and negative current collector extensions are typically gathered and welded together with a terminal tab. An insulative housing typically envelops the various components with one positive terminal tab and one negative terminal tab projecting therefrom.
The intermediate electrode and the outer counter electrodes are typically operatively spaced from one another by at least one electrolyte bearing separator. In one design, the outer counter electrodes include end edges which extend outwardly beyond end edges of the intermediate electrode. To keep the counter electrodes from contacting and shorting to the end edges of the intermediate electrode, the separators are typically configured to extend suitably beyond the end edges of at least the intermediate electrode, and typically beyond the end edges of the counter electrodes as well. In some situations, there can be a tendency to pull the intermediate electrode current collector extensions toward the counter electrode when such are subjected to vacuum during manufacture. This could result in cell shorting.
While the invention was principally motivated in addressing the above issue, it is in no way so limited. The artisan will appreciate applicability of the invention to other aspects of existing or yet-to-be-developed bicell constructions or apparatus, with the invention only being limited by the accompanying claims as literally worded and as appropriately interpreted in accordance with the doctrine of equivalents.